Background: Sleep problems are common among university students. Poor sleep is associated with impaired daily functioning, increased risk of psychiatric symptoms, and somatic complaints such as pain. Previous results suggest that poor sleep exacerbates pain, which in turn negatively affects sleep. The purpose of the present study was to determine prevalence rates, comorbidity, and role of depression as a factor of moderating the relationship between sleep and physical complaints in German university students. Samples and methods: In total, 2443 German university students (65% women) completed a web survey. Self-report measures included the Pittsburg Sleep Quality Index, three modules of the Patient Health Questionnaire, and a questionnaire on the functional somatic syndromes (FSSs). Results: More than one-third (36.9%) reported poor sleep as assessed by the Pittsburgh Sleep Quality Index. Somatoform syndrome was identified in 23.5%, and the prevalence of any FSS was 12.8%. Self-reported sleep quality, sleep onset latency, sleep disturbances, use of sleep medications, and daytime dysfunctioning were significant predictors of somatoform syndrome, whereas sleep efficiency and sleep duration influenced somatic complaints indirectly. Moderate correlations were found between stress, anxiety, somatoform syndrome, depression, and overall sleep quality. The effect of somatic complaints on sleep quality was associated with the severity of depression. Anxiety shows direct effects on somatization and depression but only indirect associations with sleep quality.